Spring on Pluto: An analysis over 30 years

Whenever it passes in front of a star, Pluto provides precious information about its atmosphere, precious because occultations by Pluto are rare. The survey achieved by researchers from Paris Observatory over several decades ...

The giant galaxy around the giant black hole

On April 10, 2019, the Event Horizon Telescope (EHT) unveiled the first-ever image of a black hole's event horizon, the area beyond which light cannot escape the immense gravity of the black hole. That giant black hole, with ...

Four questions: Here there be monsters

On April 10, the world got to see the first image taken of a black hole in space, taken by the Event Horizon Telescope, a worldwide collaboration of astronomers and astrophysicists including a substantial team at the University ...

First black hole photo confirms Einstein's theory of relativity

Black holes are long-time superstars of science fiction. But their Hollywood fame is a little strange given that no-one has ever actually seen one – at least, until now. If you needed to see to believe, then thank the Event ...

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Horizon

The horizon (or skyline) is the apparent line that separates earth from sky, the line that divides all visible directions into two categories: those that intersect the Earth's surface, and those that do not. At many locations, the true horizon is obscured by trees, buildings, mountains, etc., and the resulting intersection of earth and sky is called the visible horizon. When looking at a sea from a shore, the part of the sea closest to the horizon is called the offing. The word horizon derives from the Greek "ὁρίζων κύκλος" (horizōn kyklos), "separating circle", from the verb "ὁρίζω" (horizō), "to divide, to separate", and that from "ὅρος" (oros), "boundary, landmark".

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